The present invention relates to bearing components, and more particularly to bearing components suitable for use in bearings which are used in oils contaminated with extraneous matter having a Rockwell C hardness (hereinafter referred to as "HRC") of about 58 to about 63.
When bearings are used in oils contaminated with extraneous matter which is about 58 to about 63 in HPC, such as metal particles or molding sand, the life of the bearing reduces generally to 1/5 to 1/10 of the calculated life thereof or shorter. To improve the life of bearings in the case where they are used in contaminated oils containing extraneous matter, the present applicant has already proposed a bearing steel which is prepared from a carburizing steel and which is characterized by having a surface hardness of 63 to 66 in terms of HRC, a surface retained austenite content of 25 to 50% and a carburized case free from secondary carbide precipitates (see Unexamined Japanese Patent Publication No. 115344/1990).
However, in the case where components made of the conventional bearing steel described are used for bearings, the bearings vary in life and are not always satisfactory to use actually.